Is the EDD given to you on your scan date from your LMP or by the date of conception?

EDD is ESTIMATED. If done by scan is 38 weeks from conception. An EDD is based on the LMP (last menstrual period) and not the date of conception. The ultrasound measurements are comparing the baby to the expected size of other babies at the same gestational age. The earlier the ultrasound is done in the pregnancy, the more accurate it will be. Hope this helps! Dr. B.